运行参数对双燃料船用柴油机燃烧和排放性能的影响

为研究运行参数对天然气-柴油双燃料船用发动机燃烧和排放的影响,运用AVL_FIRE仿真软件基于4190Z_LC-2型船用中速柴油机,构建燃烧室高压循环模型。通过将仿真数据和台架试验得到的缸压曲线进行对比,验证模型的准确性。采用模型仿真,研究运行参数对燃烧和排放性能的影响。结果表明:天然气替代率可以明显改善NO的排放,过高的替代率会降低指示功率,损失部分动力性;提高进气温度可改善燃烧质量,合适的进气温度可以改善动力性和经济性;提高进气压力有增压效果,适当提高进气压力可获得较好的动力性和排放性;喷油提前角的增大,会延长滞燃期,缩短后燃期,而合适的喷油提前角可以避免工作粗暴,改善柴油机动力性。

Impact of Operating Parameters on Combustion Process and Emission in Dual Fuel Marine Diesel Engine

In order to study the influence of operating parameters on combustion and emission of natural gas-diesel dual fuel marine engine, a high-pressure cycle model of combustor was established by using AVL-FIRE simulation software based on 4190Z_LC-2 marine medium-speed diesel engine. The accuracy of the model was verified by comparing the simulation data with the cylinder pressure curve obtained from bench test. The impacts of operating parameters on combustion and emission performance were studied by model simulation. The results show that the replacement rate of natural gas can obviously increase NO emission, Too high replacement rate can reduce the indicated power and lose part of power; Increasing the intake temperature can improve combustion quality, Appropriate intake temperature can improve power and economy; Increasing the intake pressure has the effect of pressurization, Properly increasing the intake pressure can obtain better power and emission; Increasing the advance angle will prolong the ignition delay period and shorten the post-ignition period, Appropriate advance angle can avoid rough work and improve power performance.